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AGRICULTURAL LABO- 
RATORY MANUAL SOILS 



SELL 



AGRICULTURAL 
LABORATORY MANUAL 



SOILS 



BY 



EDWAKD SCOTT SELL 

PROFESSOR OF AGRICULXnKE, STATE NORMAL SCHOOIi 
ATHENS, GEORGIA 



GINN AND COMPANY 

BOSTON • NEW i'OEK • CHICAGO • LONDON 
ATLANTA • DALLAS • COLUMBUS • SAN FRANCISCO 



COPYRIGHT, 1915, BY EDWARD SCOTT SEIX 



3^5 



C'C.I,A400984 
JL'N 21 1915 



PREFACE 

The exercises in this manual have been planned for high schools, for agricultural high schools, 
and for normal schools. There are probably more exercises than most teachers will care to use hi the 
study of soils, but this will afford an opportunity to select the exercises that are best suited to the con- 
ditions and the material at hand. 

The exercises are so arranged that students may make the necessary notes with the minimum 
amount of time and trouble. Many teachers will find it an advantage to remove the sheets and give 
them to the students as needed. For some of the exercises it would not be necessary to have sufficient 
equipment for all the students to work with the same exercise at the same time. 

Accuracy in weighing materials and in performmg the experiments should be demanded of the 
students. This is not only necessary in order to secure the best results, but it is a good way to teach 
accuracy in all thmgs. 

E. S. SELL 
Athens, Georgia 



[ii] 



CONTENTS 



EXERCISE PAGE EX 

1. Origin of soils 1 20 

2. Soil particles and their separation 2 21, 

3. Microscopic examination of soil particles ... 3 22, 

4. Flocculation of soil particles 4 23, 

5. Effect of wetting on the granular structure of 24, 

soils 5 25, 

6. Weight of soils 6 26, 

7. Importance of soil moisture 7 

8. Relation of size of soil particles to water-holding' 27 

capacity 8 28 

9. Film water in soils 9 29 

Water-holding capacity of soils 10 30 

Capillarity 11 31, 

Effect of mulch on evaporation 12 32 

Determination of hygroscopic moisture, of organic 33 

matter, and of mineral matter in soils ... 13 34 

14. Rate of percolation of water through soils . . 14 3.5 

1.5. .Soil temperatures 1.5 36 

16. Effect of drainage on temperature 16 37 

17. Relation of color to temperature of soils ... 17 38, 

18. Effect of rolling on temperature 18 39 

19. Per cent of air in soils 19 40 



ERCISE PAGE 

. Effect of drainage 20 

One effect of humus and lime on clay soils . . 21 

Effect of freezing on soils 22 

Soil acidity 23 

Effect of rolling soil 24 

Erosion 25 

Power of soils to retain plant food and ferti- 
lizers 26 

. Bacteria in soils 27 

Soil inoculation 28 

. Effect of plowing under green manures .... 29 

Effect of different plant foods 30 

Crop rotation 31 

Plant food removed by crops 32 

. Tillage implements 33 

. Rainfall and temperature 34 

Commercial fertilizers 35 

. Commercial fertilizers (continued) 36 

Fertilizer test 37 

A home garden 38 

Planting plans for a home garden 39 

. Record of garden work 40 



[iii] 



LIST OF MATERIAL AND APPARATUS NEEDED 



Beakers 

Fruit jars 

Funnels 

Filter paper 

Compound microscopes 

Pie tins 

Tomato cans 

Balances, sensitive to .1 gram 

Soil tubes and stands 

Ring stands, with rings 

Graduated cylinders 

8-inch flower pots 

Blue litmus paper 

Lamp chimneys 

Mill for pulverizing soil 

Soil auger 

Labels 

Erlenraeyer flasks 

Triangles 



Glass tubes, 1^ in. x 3 ft. 

Capillary tubes 

Crucibles 

Drying oven 

Bunsen burners or alcohol lamps 

Compacting machine 

Rubber tubing, ^-in. 

Soil thermometers 

Wet-and-dry-bulb thermometers 

Garden tools 

Lime 

Paraffin 

Sand 

Clay 

Loam 

Humus 

Woods earth 

Soot 

Chalk boxes 



The above material may be bought from various scientific-supply houses, but much of it should 
be bought locally. 



[iv] 



EXERCISE 1 
OEIGEST OF SOILS 



Visit a road or a railroad cut. Find rocks that are disintegrating from the effects of freezing. Pro- 
cure rocks hat have not been affected by the "weathering processes," one that has been affected 
shghtly, and another that is nearly ready to form soil. 

Fmd evidences of the part plants play m soil formation _ either by roots or by stems. Do plants 
grow better on the hdlside or at the foot of the hill? Why? Describe below, the things you saw 
tnat relate to sou formation. •' 



[1] 



EXERCISE 2 

SOIL PARTICLES AND THEIR SEPARATION 

The day before separation is to be made, put about a tablespoonful of sand, loam, and clay soils, 
respectively, into a fruit jar two-thirds full of water. Cover and shake thoroughly. After it has stood 
for a day, shake thoroughly for fifteen minutes. Allow to settle for one minute. Pour off the roily 
water into a beaker. In order to get all except sand out of the jar, it is often necessary to pour a little 
more water into the jar, shake again, and let settle for one minute. Pour as before into the beaker. 
Be careful to pour all that will run from the jar. 

Let the water in the beaker settle for thirty minutes ; then filter all. that will run from the beaker. 

The particles left in the fruit jar will be sand ; those in the beaker, silt ; and those in the filter 
paper, clay. 

Examine the separates and note differences. Give the relative proportions of sand, silt, and clay 
m each soil. 



[2] 



EXERCISE 3 

MICEOSCOPIC EXAMINATION OF SOIL PARTICLES 

Examine sand particles magnified 75 diameters ; sUt, 75 diameters ; and clay, about 500 diameters. 
Describe with reference to the following points : 

Color — white, gray, red, brown, or black. 

Shape — angular, rounded, or irregular. 

Simple or compound structure. 

Size — coarse, medium, or fine. 
Find flocculated particles of clay (that is, a number of particles united to form a compound 
particle). 

How do soils vary m regard to (1) size of particles, (2) simple or complex character of particles, 
(3) shape of particles ? 



[3] 



EXERCISE 4 
FLOCCULATION OF SOIL PAETICLES 

Put a tablespoonf ul of clay into each of two beakers and fill each beaker nearly full of water. Stir 
well. Into one beaker put one-half ounce of hme. Stir the contents of each beaker again. Describe 
the effect that the lime has on settling the soil. 

The effect of the lime was to combiue the small particles into larger ones, thus making the clay 
settle to the bottom of the beaker more quickly. How would lime improve the mechanical condition 
of a clay soil ? 



[4] 



EXERCISE 5 
EFFECT OF WETTING ON THE GRANULAE STRUCTUEE OF SOILS 

Fill a shallow pan with clay soil ; saturate thoroughly with water, and set in the sun to dry. Note 
the cracks that form after drying. What reason can you give for the formation of the large cracks ? 
Wet again and dry. Do the cracks form as large as before ? It may be necessary to repeat the proc- 
ess several times to brmg about much difference in the granular structure. Describe the change 
effected in the soil. Would good drainage affect the granulation of a clay soil ? 



[5] 



EXERCISE 6 



WEIGHT OF SOILS 



Fill tliree smooth tin cans level full — one with sand, another with loam, and another with clay. 
Compact the soil in each can by holding the filled can three inches above a book and allowing the 
can to drop on the book. Drop each can in tliis way three times. After the soil is thus compacted fill 
the cans level full and stroke the tops with a straightedge. Record the weights and fill in as indicated 
below. Empty the cans, refill with the same kind of soil, and weigh again for a duplicate determination. 

Measure the diameter and the height of each can, and compute the number of cubic inches of soil 
contained in each. Calculate the weight of the soils per cubic foot. Calculate the weight of an acre 
to the depth of one foot, of each of the different soils. 



Kind of Soil 


Weight 
OF Can 


Can and Soil, 
First Weight 


Soil, Second 
Weight 


Average Weight 
OF Soil 


Volume 

OF Can 


Weight of Soil 
PER Cubic Foot 


Weight of Soil 
PEE Acre Foot 


Sand 
















Loam .... 
















Clay 

















[6] 



EXERCISE 7 

IMPOETAJSTCE OF SOIL MOISTURE 

Use a small, vigorous plant growing in a tomato can or flower pot. Cut a piece of cardboard so 
that it will fit about the plant and cover the can or pot. Seal the slit with paraffin or wax, so that no 
moisture can come up from below. 

Put the plant in the sunshine and cover it with a glass jar. If moisture collects on the sides of 
the glass, where does it come from ? Would you judge from this experiment that crops need large 
quantities of water ? 



cn 



EXERCISE 8 

EELATION OF SIZE OF SOIL PARTICLES TO WATER-HOLDING CAPACITY 

Place several small marbles or pebbles in a glass, and in another glass place soil equal in weight 
to the marbles or pebbles. Pour into the glass containing the marbles exactly enough water to cover 
them, and into the other glass pour exactly enough water to cover the soil. Pour off into separate 
dishes all the water that will run from each glass. From which glass does the more water come ? 
Which glass retains the more water ? 

Soils made up of small particles hold more water than those made up of coarse particles, because 
the former soils contain a greater number of particles and therefore have a greater surface to hold 
water. 



[8] 



EXERCISE 9 



FILM WATER IX SOILS 



Weigh four jars with tight covers. Number them and label each with its number and weight. 
Secure a sample of loam from a field that has been cultivated, to put in jar No. 1. (To get samples 
of soil use a soil augur and take one half of the sample at a depth of six inches and the other half at 
a depth of twelve inches.) 

Take a sample of loam from a place that has not been cultivated and that is hard and compact, 
and put it in jar No. 2. 

Secure in the same manner from cultivated fields a sample of sandy soil for jar No. 3 and one of 
clay soil for jar No. 4. 

Cover the jars tightly as soon as the soil has been put into them. Then, after they have been 
brought into the laboratory and weighed, uncover them and allow the soils to diy. The loss in weight 
will represent the amount of fihn, or capillary, water in the soils. Tell of the importance of film water 
to crop production. 





Chltivated 
Loam 


UNCULTryATED 

Loam 


Cultivated 
Sandy Soil 


CuLTIVATEaO 

Clay Soil 
















AVpi0"ht of iar and wet soil . 














Weight of jar aud dry soil 

























[9] 



EXERCISE 10 
WATER-HOLDING CAPACITY OF SOILS 

Weigh carefully the soil tube, fill with sand, and compact by using the compacting machine. 

Stand the tube in a vessel containing water to a height nearly equal to that of the surface of the 
soil, and leave the tube standmg in this position until the surface of the soil becomes thoroughly 
moistened. 

Remove the tube from the water, wipe cby, and weigh. 

In the same way determme the weight of water taken up hj loam, by clay, and by a mixture of 
loam and humus. The mixture of loam and humus should be about 25 per cent humus. 

Tabulate the data as follows : 





Sand 


Loam 


Clay 


Loam and Humus 
















Weight of tube and soil 










Weight of soil 














Weight of both and water 







































Which soil holds the most water ? Why ? What effect does the addition of humus have on the 
water-holding capacity of soils ? 



[10] 



EXERCISE 11 



CAPILLAEITY 



1. Procure a set of capillary tubes and place them in a beaker of water colored with ink. In which 
tube does the water rise the highest ? 

2. Put a piece of cloth over the end of each of tliree glass tubes three feet long. Fill one tube 
with sand, another with loam, and another with clay. Set all m water to a depth of about two inches 
and record the rise of the water in each at the close of the several periods of time indicated in the 
table below. The space between the soil particles may be compared to the capillary tubes. Why does 
the water rise higher in one soil than in another ? 



Time 


Sand 


Loam 


Clay 














One Hour 












Onp dav 












Two days 









[11] 



EXERCISE 12 

EFFECT OF MULCH ON EVAPORATION 

Procure three tin cans with holes in the bottom. Fill each about tliree-fourths full with soil. 
Pour water into the cans until it begins to drain out at the bottom. Allow the cans to drain for 
fifteen minutes. Cover the contents of the first can with a layer of dry soil to the depth of about one 
inch and keep this layer well stu-red. Make the dry-soil mulch deep enough at first so that it will not 
become wet from the soil underneath. Cover the contents of the second can with a layer of finely cut 
straw, and allow the soil in the third can to remain uncovered and undisturbed. Weigh the cans every 
day for a week and tabulate the weights according to the form below. 





Uncovered and Undisturbed 


With Coltivated-Soil Mhlch 


With Straw Mulch 




Weight 


Loss 


Weight 


Loss 


Weight 


Loss 







































































































[12] 



EXERCISE 13 

DETEEMIKATIOIT OE HYGEOSCOPIC MOISTUEE, OF OEG-ANIC MATTEE, AND OF 

MINERAL MATTER IN SOILS 

Weigh three crucibles and record weights. Put 10 grams of soil in one, 10 grams of subsoil in 
another, and 10 grams of woods earth in the tliird. Heat for one hour at 110° C. Cool in desiccator. 
Weigh. The loss in weight is the weight of the hygroscopic moisture present in the soil at the begin- 
ning of the experiment. Now heat to a dull redness. After the crucibles have burned for one hour, 
cool them in desiccator and weigh. Compute and tabulate the results as indicated below. 





Soil 


SCBSOU, 


Woods Earth 


Wpip"ht of crucible 












Weight of crucible and soil 










10 


10 


10 






Weight of soil after drying 








Per cent of water 












Weight of crucible and soil after burning . . . 








Weight of organic matter 








Per cent of organic matter 








Per cent of mineral matter 









[13] 



EXERCISE 14 
EATE OE PERCOLATION OP WATER THROUGH SOILS 

Use in this experiment sand, clay, and loam. Fill without compacting, within an inch of the over- 
flow pipes, each of the three soil tubes provided for this experiment, with one of the soils named above, 
and place a half-inch layer of gravel on the surface to prevent disturbance of the soil by flowing water. 

Connect the filled tubes with short pieces of rubber tubing, by means of the lateral ualets, and 
close with corks the ojjenings at the extreme ends of the series. 

Pour m water gently in quantities sufficient to keep the tubes almost level full and maintain the 
same water level in each tube. 

Note the time which elapses before percolation beguis from the drainage tubes, and then place an 
Erleumej^er flask beneath each. When the flow becomes constant, collect and measure carefully the 
water which percolates through the soil of each tube in thu'ty minutes. 

Determine m the same way the amount of water wliich percolates in thirty minutes through compact 
sand, clay, and loam. 

Tabvilate the results as follows: 





Loose 


Compact 


Kind of Soil 


Time for 
percolation 


Cubic centimeters of 
water in tliirty minutes 


Time for 
percolation 


Cubic centimeters of 
■water in tbirty minutes 
























1 









[14] 



EXERCISE 15 

SOIL TEMPERATURES 

To take tlie temperature of a soil, place the thermometer m the soil to a depth of about three 
inches aud allow it to remam from ten to twenty minutes. Take the temperature on a northern and 
on a southern slope, also take the temperature of clay and of sand, and of unplowed and of plowed 
fields. In each of these tln-ee groups you will probablj' find the soil mentioned second the warmer. 
AVhy ? 

Temperature of soil on northern slope 

Temperature of soil on southern slope 

Temperature of soil of unplowed field 

Temperature of soil of plowed field 

Temperature of clay soils 

Temperature of sandy soils 



[15] 



EXERCISE 16 

EFFECT OF DRAINAGE ON TEMPEEATUEE 

Fill the receptacle on the hygrometer with water. At the same time fill a beaker half full of 
water and place a thermometer in it. In about thirty minutes record the temperature of the au-, of 
the wet bulb, and of the water m the beaker. 

Why is the wet bulb colder than the water in the beaker ? With other conditions the same, why 
is a well-ch-ained soil warmer than a wet soil ? 

A wet-and-dry-bulb thermometer may be made by attaching two thermometers to a small board 
and tying a piece of cloth around the bulb of one of the thermometers. The cloth should be long 
enough to draw up water from a receptacle attached to the board and is by this means kept wet. A 
wet-and-dry-bulb thermometer is sometimes called a hygrometer. 

Temperature of dry bulb 

Temperature of water 

Temperature of wet bulb 



[16] 



EXERCISE 17 

RELATION OF COLOR TO TEMPERATURE OF SOILS 

Fill two small boxes nearly full with loam soil. Cover one with chalk dust or lime and the other 
with soot. Bury tlie bulb of a thermometer about an inch deep in each box. See that the thermom- 
eters are placed at equal depths and perpendicular to the surface. Read the thermometers from time 
to time. Why are dark soils warmer than light ones ? Results may be obtained more quickly by 
placing the boxes in the sunshine. Read the temperatures every ten minutes for one hour and record 
in the blanks below. 



Kind of Soil 


Tempebatueb 


At end of 10 min. 


At end of 20 min. 


At end of 30 min. 


At end of 40 min. 


At end of 50 min. 


At end of 60 min. 


Dark soil .... 














Light soil .... 















[17] 



EXERCISE 18 
EFFECT OF EOLLING ON TEMPEEATURE 

Pulverize the soil on two small plots in a field or garden. Leave the soil of one plot loosely 
prepared, and roll or pack the soil of the other plot. Place a soil thermometer to the depth of three 
inches m each plot and allow the thermometers to remain in the soil from ten to twenty minutes; 
then read the temperatures and record them m the blanks below. 

If the weather is clear and warm, rolling will make the soil warmer, but if the weather is cloudy 
and cold, the effect will be to make the soil colder. For this reason the temperature of the soil in 
each plot should be taken several times, under differing weather conditions. 



Date 
















Temperature of rolled soil 
















Temperature of loose soil 















[18] 



EXERCISE 20 

EFFECT OF DEAINAGE 

Secure two S-inch flower pots. Coat oue with paraffin and cork the dramage hole in the bottom. 
Fill both pots with fertUe soil and plant two or three grains of corn in eacli. Keep well watered until 
the plants grow several inches high. Make notes of whatever difference j'ou find in the growth of 
the plants. Read the temperature of the soil in each pot at different times and record in the blanks 
below. 

Is an- necessary for plant growth ? If the soil is filled with water, will the ah be excluded ? 



Pate 


















Temperature of drained soil .... 














Temperature of undrained soil . . . 















[20] 



EXERCISE 21 

ONE EFFECT OF HUMUS AND LIME ON CLAY SOILS 

Procure tlu-ee quarts of clay. To oue quart add water, to another add water and about one-fourth 
Its volume of humus, and to the thu:d add hme milk (hme milk is made by putting one tablespoonful 
ot hme m about one-half pint of water). Make the clay thus treated into balls and set them aside to 
dry. When the balls become dry, pulverize them and note the hardness of each. What is the effect 
of workmg clay wet ? What is the effect of humus and of hme on clay soils ? 



[21] 



EXERCISE 22 

EFFECT OF FREEZING ON SOILS 



Puddle a pmt of clay, mold it into a ball, and let it dry. In freezing weather moisten the ball and 
put It out of doors oyernight. If it does not break up the first night, moisten it again and subiect it 
once more to the action of frost. From this result, what would you say of the practice of fall-plowing 
clay soils .'' Is there any advantage in fall plowing other than that it pulverizes the soil ? 



[22] 



EXERCISE 23 
SOIL ACIDITY 

Select at least thi-ee samples of soil from differeut parts of a field. Make a ball from each sample 
of soil, moistening if necessary. Break in two, place a piece of blue litmus paper between the parts, 
and press the soil firmly together again. After about five minutes examine the paper. If it has turned 
pink or red, soil acidity is indicated. The amount of acidity is indicated to some extent by the iaten- 
sity of the color and by the rapidity with which it develops. 

Mark the ]Dlace where each sample is selected and if a sample proves to be acid, study the loca- 
tion and type of soil as well as the general conditions existing where this particular sample was 
selected. What effect does acidity have on plants ? on the growth of bacteria on legumes ? What 
will correct soil acidity? 



[23] 



I 



EXERCISE 24 
EFFECT OF ROLLING SOIL 



Plant radish seeds one inch deep in two flower pots. In both pots have the soil loosely prepared 
After planting the seed, firm the soil in one pot, leaving that in the other loose. Note the time 
required to germinate the seeds in each pot. 

Moisture is one essential of seed germination. If the soil is rolled, it brings more particles of soil 
in contact with the seed and therefore furnishes more moisture for germination. 



[24] 



EXERCISE 25 

EROSION 

Weigh a tomato can and fill it with water running in a ditch after a rain. Water flowing rapidly- 
down a liillside will be better. Evaporate the water by boiling it until the soil which it contained is 
left dry. The results should be placed in the blank below. Would you consider the loss from erosion 
veiy great ? 

The soil that is lost by erosion is the most valuable that the farmer has because it is the finest and 
gives up its plant food the most readily. 



AVei^ht of Ctiii 








AVeiffht of ■wat8r 








Weio'ht of soil 








Ppr cent of soil 









[25] 



EXERCISE 26 
POWER OF SOILS TO EETAIN PLANT FOOD AND FERTILIZERS 

Tie a piece of cheesecloth over one end of each of three lamp chimneys. Fill one cliimney within 
an inch of the top with sand ; another, with clay ; and the third, with loam. 

Pour into the chimneys muddy water or manure liquid (to make manure liquid, fill a bucket 
one-fourth full of manure, fill with water, and let stand for one day). Place beakers underneath the 
chimneys to catch the water. 

Note the color of the water after it has percolated through the soil. How does this show the 
ability of soils to retain plant food and fertilizers ? 



[26] 



EXERCISE 27 

BACTERIA IN SOILS 



I 



Secure a small sample of fertile soil and place on a slide in a few drops of water. Examine with 
compound microscope that will magnify from 500 to 1000 diameters. 
What shape do these bacteria have ? Are there many ? 



[27] 



EXERCISE 28 

SOIL INOCULATION 

Fill two 8-inch flower pots with good loam. The soil should be obtained from a field in which 
no alfalfa has been grown. 

Plant a few alfalfa seeds in each pot. Inoculate the soil in one pot by using some soil from a 
field where alfalfa has been successfully grown or secure artificial cultures of bacteria. Describe the 
difference in growth of the plants in the two pots. 

Bacteria for alfalfa may be obtained at any seed store or from the United States Department of 
Agriculture. This experiment may be conducted to better advantage on two field plots. 



[28] 



* 



EXERCISE 29 
EFFECT OF PLOWING UNDER GREEN MANURES 

Tie a piece of musliii over one end of each of three lamp chimneys. Fill one with loam. Fill 
another two-thirds full of loam, then add a two-inch layer of manure and fill to the top with loam. 
Fill the remaining chimney two-thmls full of loam, then add a two-inch layer of grass or other green 
material and fill to the top with loam. 

Place the chimneys in an inch of water and note the rise of moisture. Can you see any reason why 
seeds should not be planted a short time after turning under green manure ? Why ? 



[29] 



EXERCISE 30 
EFFECT OF DIFFERENT PLANT FOODS 

Fill seven 8-inch flower pots with sand. Number and label the pots. Add plant foods as follows : 

1. Nothing. 

2. 10 orams of lime. 

3. 10 grams of lime, 1 gram of potassium chloride. 

4. 10 grams of lime, 1 gram of acid phosphate. 

5. 10 grams of lime, 1 gram of sodium nitrate. 

6. 10 grams of lime, 1 gram of potassium chloride, 1 gram of acid phosphate, 1 gram of sodium 
nitrate. 

7. About one pint of stable manure. 

Mix the materials in each pot and then plant live kernels of wheat in each pot. Record the growth 
of the plants from day to day, noting the amount of growth and the color. 



[30] 



EXERCISE 31 



CROP EOTATION 



Reasons for crop rotation : (1) different crops remove different amounts of plant food ; (2) crops 
feed at different depths ; (3) economy of labor ; (4) failure of one crop will not mean entire failure ; 
(5) improvement of the soil. 

Factors to be considered : (1) in four-year rotation the farm must be divided into four equal parts, 
in tlu-ee-year rotation, into three equal parts, etc. ; (2) the money crop ; (3) animals to be fed. 

Fill out the blanks below, indicating crops adapted to j'our state to make a four-year rotation. 



Field 










1 










2 










3 










4 











Plan a rotation for a 150-acre farm that will produce 50 acres of cotton, 50 acres of corn, 50 acres 
of oats, and 100 acres of cowpeas. 



I 



Field 








1 








2 








3 







I 



[31] 



I 

I 



EXERCISE 32 
PLAJSTT FOOD EEilOVED BY CROPS 

If an acre of com, yielding 40 bushels, removes 35 pounds of nitrogen, 15 pounds of phosphorus, 
and 12 pounds of potash, how many pounds of nitrate of soda (IG per cent), acid phosphate (IG per 
cent), and muriate of potash (50 per cent) will it take to supply the plant food removed ? 

What is the difference in the value of the plant food removed by 100 acres of corn, yieldino- 
40 bushels per acre, and the market price of the corn ? 

Nitrogen is worth 1 7 cents per pound, phosphorus 5 cents per pound, and potassium 5 cents per pound. 



t 



I 
I 



I 



[32] 



% 



EXERCISE 33 

TILLAGE IMPLEMENTS 



Make a list of the different kinds of plows and discuss the usefulness of each. In the same man- 
ner list the different kinds of harrows, of cultivators, and of rollers, and discuss the usefuhiess of the 
several kinds of each implement. 



[3.3] 



EXERCISE 35 

COMMEECIAL FEETILIZEES 

1. Assuming that nitrogen is worth 1 7 cents per pound, phosphorus 5 cents per pound, and potas- 
sium 5 cents per pound, calculate the commercial value of the plant food m a ton of fertilizer with 
the following composition: («) 10-2-2*; (i) 8-3-2; (c) 5-4-5. 

2. Calculate the percentage of nitrogen, phosphorus, and potassium in a mixture of 

600 pounds of nitrate of soda (15 per cent) 
1000 pounds of acid phosphate (16 per cent) 
400 pounds of kamit (12 per cent) 

3. How many pounds of each of the materials used in 2 would it take to make a ton of fertilizer 
aualyzmg 8-2-3 ? 

Note. Problem 3 is one of compound proportion. The per cent of plant food in a given material is to the total 
amount of that kind of plant food wanted in the mixture as 100 is to x. To determine the number of pounds of acid 
phosphate needed in this problem, we should have 

16 :160 (or total number of pounds in a ton) : :100 : x 
16 x = 16,000 
X = 1000 

* A 10-2-2 fertilizer contains 10 per cent phosphorus, 2 per cent nitrogen, and 2 per cent potassium. (In some states the 
order is nitrogen, phosphorus, potassium, in which case the formula 10-2-2 would mean 10 per cent nitrogen, 2 per cent 
phosphorus, and 2 per cent potassium.) 



t 



[35] 



EXERCISE 36 

COMMEECIAL FEETILIZEES (Continued) 

1. How many pounds of acid phosphate (16 per cent), kainit (12 per cent), and cottonseed meal 
(6^ per cent nitrogen, 2.8 per cent phosphoric acid, 1.8 per cent potash) would it take to make a 
fertilizer analyzing 8-2-3 ? (When using materials containing more than one plant food, first find 
out the number of pounds needed to furnish the required amount of the plant food of which this 
material is primarily the carrier. Cottonseed meal is primarily a carrier of nitrogen, hence determine 
first the number of pounds of cottonseed meal needed to furnish the amount of nitrogen required 
in the mixture.) 

2. Using the same materials as in problem 1, determine the number of pounds of each to make a 
fertilizer analyzing 9-2-2. 

3. Use some of the materials mentioned in the above problems to make a small amount of 9-2-2 
fertilizer; 100 grams will be a sufiicient amount of the mixture. 



[36] 



EXERCISE 37 

FEKTILIZEK TEST 

Lay off ten plots about eighteen by twenty feet on as nearly uniform soil as possible. The plots 
may be larger or even smaller. Care should be taken to have the soil uniformly prepared. Put 
fertilizer on the plots as follows: 

Plot 1, nothing. 

Plot 2, nitrate of soda at the rate of 160 pounds per acre. 

Plot 3, acid phosphate 300 pounds per acre. 

Plot 4, muriate of potash 80 pounds per acre. 

Plot 5, nitrate of soda 160 pounds per acre and acid phosphate 300 pounds per acre. 

Plot 6, nitrate of soda 160 pounds per acre and muriate of potash 80 pounds per acre. 

Plot 7, acid phosphate 300 pounds per acre and muriate of potash 80 pounds per acre. 

Plot 8, acid phosphate 300 pounds per acre, muriate of potash 80 pounds per acre and nitrate of 
soda 160 pounds per acre. 

Plot 9, barnyard manure at the rate of 10 tons per acre. 

Plot 10, lime at the rate of one ton per acre. 
Oats or some other crop that can be planted in the fall should be planted on the plots so that the 
results may be studied durmg the school term. 

Notes should be made as to the effects of the different plant foods on the growth of the plants as 
well as on the yield. 



[37] 



EXERCISE 38 



A HOME GARDEN 



Draw a plan of a garden to supply a home with a succession of vegetables. The size of the family 
must of course be considered. Indicate on the plan the distance between the rows, the vegetables to 
be planted in each row, etc. If the garden is to fit a certain piece of ground, this space should be 
measured and a map of it made the basis for the garden plan. 

On a farm it is important that the garden be arranged for convenience in horse cultivation. 
It is very desirable and would be profitable for farmers to grow a greater variety of vegetables than 
is now commonly grown. 



[38] 



EXERCISE 39 
PLANTING PLANS FOR A HOME GARDEN 



By using seed catalogues, determine the amount of seed, cost of seed, and time of planting for 
the garden planned iii the previous lesson. 

Also list the kind and amount of fertilizers as well as the manner of applying them. Give sug- 
gestions for the preparation of the soil. 



[39] 



EXERCISE 40 

EECORD OF GARDEN WORK 
Kind of soil ^ 



Operations of preparation, with dates_ 



Size of plot- 



Amount of fertilizer used- 



Amount of fertilizer per acre- 
Kinds of fertilizer 

Date of planting 



Kind of seed planted- 



Depth at which seed was planted- 



Which was planted deeper ? Why ?_ 



Date of germination 

Time from planting to germination- 
Date of first cultivation 



Size of plants at first cultivation- 
Date of second cultivation 



Size of plants at second cultivation- 
Date of tliird cultivation 



Size of plants at third cultivation- 



Other operations or applications of fertilizer- 



Date of maturity- 



Time from planting to maturity- 



Have plants been affected by diseases or insect pests ? If so, what remedy was used ?- 

[40] 



